1. Statement of the Technical Field
The inventive arrangements relate to phase shifters, and more particularly to phase shifters which are broad-band, low-loss radio frequency (RF) microelectromechanical systems (MEMS) devices.
2. Description of Related Art
Communication systems, such as broadband satellite communication systems, commonly operate anywhere from 300 MHz (UHF band) to 300 GHz (mm-wave band). Such examples include TV broadcasting (UHF band), land mobile (UHF band), global positioning systems (GPS) (UHF band), meteorological (C band), and satellite TV (SHF band). Most of these bands are open to mobile and fixed satellite communications. Higher frequency bands typically come with larger bandwidths, which yield higher data rate operation. Phase shifters used in these types of systems need to operate with relatively low losses, e.g., less than one decibel (dB) of insertion loss, at such frequencies.
Miniaturized phase shifters fabricated as monolithic microwave integrated circuit (MMIC) phase shifters are commonly used in broadband communications systems due to stringent constraints imposed on the components of such systems, particularly in satellite-based applications. Currently, available MMIC digital phase shifters operate with relatively high insertion loss (i.e., 7 dB of insertion loss at 18.5 GHz).